RHEVM: The effect of a MAC address change

Latest response

Hello

 

Can you tell me if a change of MAC address of the primary NIC interface on a RHEV Manager will cause any issues with RHEV-M ?

For instance, if I were to replace a faulty NIC card on hardware that serves as my RHEV-M ? 

I can't see it recorded anywhere in a dump of the manager database but just wanted to be sure that its not refered to in the manager installation anywhere.  

 

Thanks

Responses

As long as the IP and FQDN are the same, this is not a problem

Thanks.  On a similar node then, I did notice that the MAC's of the hypervisors ARE recorded in the database.

If we had to replace a faulty NIC on the hypervisor hardware what effect would this have to RHEV-M ?   Would it automatically amend and show correctly in the admin GUI or would we have to destroy the network config / bond  and recreate it ?

> Would it automatically amend and show correctly in the admin GUI or would we have to destroy the network config / bond  and recreate it ?

 

At this moment, RHEV generates uuid for a hypervisor using systemid from dmidecode and lowest mac address available on the host. UUID will be "systemid_mac". If changing the NIC causes the lowest mac id to change, the uuid will change on the system, but not on the db. This causes vdsm-reg to think that the system is not registered with RHEV-M and will try to re-register when it runs vdsm-reg netxt time, usually after next reboot. This may cause some annoying messages, log file fill up with messages "Cannot register system", but will not cause any functional issues.

 

Solution for this is to either re-register the system to rhev-m or update the uuid in database. The latter can be done with help from Red Hat support.

 

The mac address is also stored in the interface details of the hypervisor in database, but I doubt they have any functional use case except displaying mac address on GUI.

 

If you re-register the system, that problem, if any, will also get cleared.

Thanks Sadique - Spot on.